The present invention concerns a new process for the preparation of an extract of embryonic mammalian organs, which extract is free of nonpolar constituents and constituents having a high molecular weight. The extract is prepared according to a new extraction process in which the first extraction step of the finely divided embryonic organs is performed with a mixture of water and a water miscible organic solvent, which mixture contains at least 70 vol.-% referred to the total volume of said mixture of the water miscible organic solvent and has an about neutral pH-value in order to avoid degradation of high molecular proteins. The recovered extract, accordingly, contains only such polar constituents having a molecular weight of lower than 5000 which had been present in the fresh embryonic mammalian organs and no materials produced through a degradation of proteinous constituents.
The produced extracts are used as active ingredients of pharmaceutical preparations for the treatment of reduced blood flow through the brain or peripheric organs and as active ingredient of pharmaceutical preparations for the treatment of acne vulgaris.